Comparison of mechanized systems for thinning Ponderosa pine and mixed conifer stands

Abstract

We studied three systems for thinning pine plantations and naturally-regenerated stands on the Stanislaus National Forest, California. All three produced small sawlogs and fuel chips. The whole tree system consisted of a feller buncher, skidder, stroke processor, loader and chipper. The cut-to-length system included a harvester, forwarder, loader and chipper. A hybrid system combined a feller buncher and harvester to produce bunches of small whole trees for fuel, and bunches of long delimbed sawlogs. The hybrid bunches were skidded to a landing where they were chipped or loaded. The cut-to-length system had higher costs per unit of material and yielded less fuel than the other systems. The cut-to-length system damaged fewer trees in the natural stand than the other systems, but damage levels were low for all systems. Other environmental impacts - on soil, fuel levels, insect activity and stand growth - are still being evaluated.

Citation

Hartsough, Bruce R.; McNeel, Joseph F.; Durston, Thomas A.; Stokes, Bryce J. 1994. Comparison of mechanized systems for thinning Ponderosa pine and mixed conifer stands. 1994 international winter meeting sponsored by the American Society of Agricultural Engineers. ASAE Pap. 94-7513. St. Joseph, MI; American Society of Agricultural Engineers. 20 p.